"""
   author: 陈亚敏
   data: 2021/10/29  17:13
   project: 1
"""
# #第一题：--------------------------------------------------------------
# while 1:
#     pm_25=input("please input the value of PM2.5:")
#     if pm_25=='q':
#         break
#     elif 0<int(pm_25)<=50:
#         print("优")
#     elif 50<int(pm_25)<=100:
#         print("良")
#     elif 100 < int(pm_25) <= 150:
#         print("轻度污染")
#     elif 150 < int(pm_25) <= 200:
#         print("中度污染")
#     elif 200 < int(pm_25) <= 300:
#         print("重度污染")
#     elif int(pm_25) >300:
#         print("严重污染")
# print("886")
# #第二题：--------------------------------------------------------------
# import random as rd
# gold=1000
# times=0
# winning=0
# while 1:
#     num1 = rd.randint(1, 6)
#     num2 = rd.randint(1, 6)
#     num3 = rd.randint(1, 6)
#     result = num1 + num2 + num3
#     guess = input("赌一赌搏一搏单车变摩托，开大还是开小？：(exit退出)")
#     if guess=='exit':
#             break
#     elif result>=11:
#         times+=1
#         if guess=="大":
#             winning+=1
#             gold += 100
#             print(num1,num2,num3,"大！猜对了！金豆+100，余额：",gold)
#         else:
#             gold -= 100
#             print(num1,num2,num3,"大！猜错了！金豆-100，余额：",gold)
#     elif result<11:
#         times += 1
#         if guess=="小":
#             winning+=1
#             gold += 100
#             print(num1,num2,num3,"小！猜对了！金豆+100，余额：",gold)
#         else:
#             gold -= 100
#             print(num1,num2,num3,"小！猜错了！金豆-100，余额：",gold)
#
# print("*"*30)
# print("恭喜发财，欢迎下次再来！")
# print("本轮进行了%d次游戏"%times,"胜利%d次"%winning,'胜率为%.2f%%'%((winning/times)*100),"余额%d个金豆"%gold)
#
# #第三题：--------------------------------------------------------------
num1=input("please input a nubmer:")
num3=num1[::-1]
num2=""
for i in range(len(num3)):
    if (i+1)%3==0 and i !=(len(num1)-1):
        num2+=num3[i]+','
    else:
        num2+=num3[i]
print("该数千分位格式为：",num2[::-1])
#第四题：--------------------------------------------------------------
# for i in range(1,10):
#     for j in range(1,10):
#         print(i,"*",j,"=",i*j,end='     ')
#     print("\n")